Download Term 1: Thermodynamics and Related Energy Concepts and more Quizzes Chemistry in PDF only on Docsity!
Thermodynamics
The study of the conversion of energy into work and heat and its relation to macroscopic variables such as temperature, volume and pressure. TERM 2
Energy
DEFINITION 2 The capacity to do work or transfer heat. TERM 3
Work
DEFINITION 3 Energy used to cause an object with mass to move against a force. TERM 4
Heat
DEFINITION 4 Energy used to cause the temperature of an object to increase. TERM 5
Kinetic Energy
DEFINITION 5 The energy of motion. The magnitude of the kinetic energy (E_k) of an object depends on its mass (m) and speed (v). E_k=(1/2mv^2)
Potential Energy
(E_p)Energy an object posses as a result of its composition or its position with respect to another object. (m) is equal to mass, (h) is the height of the object to some reference height, and (g) is the gravitaional constant- 9.8m/s^2. E_p= (mgh) TERM 7
Force
DEFINITION 7 Any kind of push or pull exerted on an object. TERM 8
Electrostatic Potential Energy
DEFINITION 8 Arises from interections between charged particles. Electrostatic potential energy (E_el) is proportional to the electrical charges of the two interacting objects (Q_1), (Q_2), and is inversly proportional to the distance seperating them. The constant of proportionality (k)-8.9910^9 J-m/C^2 and distance are also factored. E_el=(kQ_1*Q_2)/(d) TERM 9
Chemical Energy
DEFINITION 9 Energy due to potential energy stored in the arrangement of atoms. TERM 10
Joule (J)
DEFINITION 10 1J=1(kg-m^2)/(s^2)
Open System
A system where energy and matter can both be exchanged with its surroundings. (ex. a boiling pot without a lid on it) TERM 17
Work Equation
DEFINITION 17 Work=Force*Distance TERM 18
Force Equation
DEFINITION 18 Force=Mass*Gravitaional Constant (9.8 m/s^ TERM 19
First Law of Thermodynamics
DEFINITION 19 Energy can neither be created nor destroyed. Energy is conserved. TERM 20
Internal Energy
DEFINITION 20 Total of all energy, including potential and kinetic energy, possesed by a system.
Delta E
The change in internal energy, defined by the final product (E_final) and the beginning product (E_initial). Delta E= E_final-E_initial Needs 3 parts, (1) a number, (2) a unit, (3) a sign-positive or negative. also: Delta_E=heat(q)+work(w) When heat is added to a system or work is done on a system, it's internal energy increases. TERM 22
Endothermic
DEFINITION 22 A process in which a system absorbs heat. TERM 23
Exothermic
DEFINITION 23 A process in which a system absorbs heat. TERM 24
State Function
DEFINITION 24 A property of a system that is determined by specifying teh system's condition, or state (in terms of temperature, pressure...). The value of a state function depends only on the present state of the system, not the path that the system took to reach that state. TERM 25
Pressure-Volume
Work
DEFINITION 25 Work involved in the expanssion or compression of gases. W=-P*(Delta V) where Delta V=(V_final)-(V_initial)
Molar Specific Capacity(C_m)
Heat capacity of one mole of a substance. TERM 32
Specific Heat(C_s)
DEFINITION 32 The heat capacity of one gram of a substance. Specific Heat= (Quantity of heat transfered)/(Grams of substance* (temperature change) or C_s=(q)/(m)(Delta T) or q=(C_s) (m)*(Delta T) TERM 33
Bomb Calorimeter
DEFINITION 33 A device for measuring the heat evolved in the combustion of a substance under constant-volume q_reaction=(-C_cal)* (Delta T) TERM 34
Hess's Law
DEFINITION 34 If a reaction is carried out in a series of steps, Delta H for the overall reaction will equal the sum of the enthalpy changes for the individual steps. For a particular set of reactions and products, Delta H is the same whether the reaction takes place in one step or a series of steps. TERM 35
Standard State
DEFINITION 35 A definite set of conditions to which most enthalpies are tabulated used for comparing enthalpies.
Standard Enthalpy Change
The change in enthalpy in a process when all reactants and products are in their stable forms at 1 atm pressure and a specified temperature, commonly 25 degrees celcius. TERM 37
Standard Enthalpy of Formation
DEFINITION 37 The change in enthalpy for the reaction that forms 1 mole of the compound from its elements, with substances in their standard states. elements(in standard state)->compound(in standard state)
